Programming with HLLAPI

HLLAPI supports three different languages: C, COBOL, and FORTRAN. The source code requirements for calls are different for each supported language. This is because the high-level languages handle data in different ways and reserved words or syntax vary. Consult the following for information about how to use direct calls in each of the supported languages and source code preparation is discussed.

• HLLAPI Guidelines for C Programs
• HLLAPI Guidelines for COBOL Programs
• HLLAPI Guidelines for FORTRAN Programs

Programs using HLLAPI functions are typed in as source code in a compiled and linked supported language. Source programs in any supported language need the following six libraries to create the final executable:

• libhllapi.a
• libg3270.a (valid only in HCON 1.3 versions)
• libiconv.a
• libcur.a
• libodm.a
• libfxfer.a

HLLAPI Guidelines for C Programs

The following guidelines are helpful in preparing applications that use HLLAPI functions in C language.

Source Code Preparation

There are no required statements for the C language that call HLLAPI function. However, instead of defining their own header files, the C applications can use the sample hapi_ c.h program, which has defined constants and structures.

HLLAPI Functional Call Syntax

The syntax for calls to HLLAPI functions in the C language is:

hllc( func, apistring, len, ret)
int *func;
char *apistring;
int *len;
int *ret;

Compiling and Linking

To compile a C source program sample.c into an executable, use this command with the following order:

cc sample.c (libg3270.a in HCON 1.3 versions only) -lhllapi -liconv -lcur -lodm -lfxfer -o test

HLLAPI Guidelines for COBOL Programs

The following guidelines are helpful in preparing applications that use HLLAPI functions in COBOL language.

Source Code Preparation

There are no required statements for the COBOL language that call HLLAPI functions. However, the COBOL applications can create their own include files according to the definition provided by the hapi_ c.h sample program.

HLLAPI Functional Call Syntax

The syntax for calls to HLLAPI functions in the COBOL language is:

CALL "COBLIM" USING FUNC STR DLEN RETC.

The parameter types are defined as:

01 FUNC PIC S9(4) COMP.
01 DLEN PIC S9(4) COMP.
01 RETC PIC S9(4) COMP.
01 STR.
03 FILLER PIC X(256).

For applications migrating from an IBM OS/2 environment, the parameters are defined as:

01 FUNC PIC 9(4) COMP-0.
01 DLEN PIC 9(4) COMP-0.
01 RETC PIC 9(4) COMP-0.
01 STR. 03 FILLER PIC X(256).

Compiling and Linking

To compile the COBOL source program test.cob into an executable, use this command with the following order:

cob -x test.cob -lhllapi -lg3270 -liconv -lcur -lodm -lfxfer -o 'test'

HLLAPI Guidelines for FORTRAN Programs

The following guidelines are helpful in preparing applications that use HLLAPI functions in FORTRAN language.

Source Code Preparation

There are no required statements for the FORTRAN language that call HLLAPI function. However, the FORTRAN applications can create their own include files according to the definition provided by the hapi_ c.h file.

HLLAPI Functional Call Syntax

The syntax for calls to HLLAPI functions in the FORTRAN language is:

hllc(FUNC, %REF(CHAR_ARG), LEN, RET)

The parameter types are defined as:

INTEGER*4 FUNC, LEN, RET CHARACTER*256 CHAR_ARG

Compiling and Linking

To compile a FORTRAN source program test.f into an executable, use this command with the following order:

xlf test.f -lhllapi -lg3270 -liconv -lcur -lodm -lfxfer -o test

This compilation will include all the needed libraries in the final executable.

HLLAPI Functions by Function Number

The following lists the HLLAPI functions organized by function number.

Summary of Prerequisite Calls for HLLAPI Functions

This table lists the prerequisite calls for each HLLAPI function. Prerequisite calls are required when using any of the application programs.